Piston for internal-combustion motors



. L. P. MOOERS. PISTON FOR INTERNAL COMBUSTION MOTORS. APPLICATION FILED JUNE 28, 1916. nsuawzo ocr. 24, 1919. 1,347,819.

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PISTON FOR INTERNALCOMBUSTION MOTORS. APPLICATION FILED JUNE 28, 1916. RENEWED OCT. 24, 1919.

Patented July 27, 1920.

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PISTON FOR INTERNAL COMBUSTION MOTORS. APPLICIATION FILED 1uNE'28, I916. RENEWED 00124, 1919.

1-,34=7,8 1 9 I Patented July 27, 1920.

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LOUIS P. MOOERS, OF CINCINNATI, OHIO, ASSIGNOR, BY DIRECT AND MESNE ASSIGN- MENTS, TO THE CLEVELAND TRUST COMPANY, OF CLEVELAND, OHIO, A CORPORA- TION OF OHIO.

PISTON FOR INTERNAL-COMBUSTION MOTORS.

Specification of Letters Patent.

Application filed June 28, 1916, Serial No. 106,502. Renewed October 24, 1919. Serial No. 333,111.

.conditions which exist within an internal combustion motor cylinder, including the stresses and strains imposed upon the piston, principally during the explosion stroke and by the high heat generated at this time, which heat must be efiiciently and economically (a) utilized in the translation of heat into mechanical energy and (b) that not translated into mechanical energy properly dissipated.

My present invention comprises improvements on the joint invention of Edward O. Spillman and myself, disclosed in Letters Patent of the United States No. 1,092,870. It contemplates simplifying the construction and manufacture of pistons of this patented type by making them in two or more parts, if desired of different materials, and of considerably lightening the construction as compared with the integral cast structure illustrated in the said patent.

Purely for the purposes of disclosure herein I have selected to illustrate and describe one construction of internal combustion motor, skirted piston and a modification thereof embodying my improvements.

In the drawings, Figure 1 is a side elevation of a piston embodying my improvements.

Fig. 2 is a section on the line 22, Fig. 1.

Fig. 3 is a section on the line 33, Fig. 2.

Fig. 4 is a bottom plan view.

Figs. 5 and 6 are views similar to Figs. 2 and 3, respectively, of a modified type of piston embodying my invention.

Fig. 7 is a section on the line 77 of Fig. 5.

1 is the skirt, body or guide portion of v the piston, which may be made of a section of steel tubing or a steel stamping having diametrically opposed apertures through it,

1 1", concentric with the axis of the wrist pin bosses, to permit the insertion and withcooperate, that it should notbe necessary to machine this section or guide portion of the piston, although it will be understood that if desired it may be machined or treated in any preferred mechanical manner.

3 indicates the head or top wall of the piston. It comprises, preferably, an end wall 3, a peripheral wall 3" preferably suitably grooved, as indicated at 3", to receive suitable piston rings, and a depending or inwardly turned annular flange 3 concentric with the axis of the wall 3. This head portion of the piston may be made of a steel forging or stamping or formed of aluminum or aluminum alloy or any other suitable material. Its principal functions are to assist in translating the heat of the burning gases in the motor cylinder into mechanical motion, dissipate a part of that heat principally by convection and to carry the piston properly with the inner walls of the cylinder with which they are adapted to contact.

at is a connector or tie piece by means of which the skirt 1 is properly related to and connected with the head 3. This inner part 4- 0f the piston may be made in any suitable manner, as for example from a malleable iron, steel or aliiminum alloy casting. Preferably it carries intermediate its ends a pair of alined tubular bearing bosses 4:, 1 The boss 4: may have a depending lug 4 formed with a screw-threaded opening to receive a suitable locking bolt or screw to secure in a well known manner the wrist pin to be mounted in the said boss. This connecting piece 4 is preferably of tapering cross-section longitudinally, as indicated, having at its outer end an annular cylindrical section 4 adapted to receive the flange 3' of the head 3, and at its inner or lower end, a cylindrical section 4 of suitable size to engage the inner wall of the skirt 1 near the bottom thereof. A plurality of holes 4: are provided through the connecting piece 4:, preferabl adjacent the points at which its lower en contacts with the inner Wall of the skirt 1. These holes or ducts provide oil escapes or drain passages for lubricant or oil which may collect between the skirt 1 and connecting piece 4.

The flange 3 of the head 3 and section 4 of the connector 4 may be connected together in any suitable manner. For this purpose I have shown the flange 3 to be externally and the section 4 to be internally screw-threaded and thus fitted together. Where this sort of connection is made, the flange 3 or any part of it may be expanded or otherwise suitably treated so as to insure that the parts will be securely held together.

-The lower end 4 of the connecting piece 4 may be connected to the skirt 1, likewise in any suitable manner. Where these elements are made of metals which may be welded together, I have had in mind to spot weld them securely to each other, in the wellknown manner. I

In the modification of my invention, illustrated in Figs. 5, 6 and 7, my improved piston is made in two rather than three pieces or sections. The head 3 may be constructed as hereinbefore described. "The body or skirt 1 and connector 4 in this embodiment of my invention are preferably formed integrally, the connection between them being made at the lower end of the connector adjacent the lower end of the skirt. They may be made from cast iron or any other suitable metal. The-top or head, as first above indicated, may be a steel forging, a stamping, or made from aluminum alloy or any other metallic alloy having a relatively low specific gravity. In this modified form of piston embodying my invention the drainage ducts or holes 4 extend preferably through the connector 4, as indicated, adjacent its connection with the skirt 1.

It will be understood that the sleeve or skirt *1 may be constructed so as snugly to fit the inner walls of the motor cylinder, whereas the head 3 may be given a considerable amount of clearance between its outer surface and the inner wall of the cylinder to allow for all necessary-expansion of the head due to the hi h temperatures to which it is subjected. T he heat absorbed by the head is transferred downwardly by the connecting piece 4 to the lower end of the skirt 1, and much of it is dissipated by radiation, so that the skirt is kept relatively cool and may be readily lubricated to provide and maintain the proper working relationship between it and the inner wall of the motor cylinder with which it co-acts. The fit between the skirt and the inner wall of the cylinder, as before indicated, may be a snug sliding fit, and the area of the skirt which co-acts with the inner wall of the motor cylinder is such as to insure against slapping or rapping of the piston against the inner wall of the cylinder. In fact, objectionable so-called piston slap, incident to the operation of numerous types of pistons for use,

in internal combustion motors, substantially is eliminated by the use of a piston constructed in accordance with my invention. Furthermore, a piston embodying my improvements herein described practically eliminates so-called oil pumping or transfer of an undue amount of oil or lubricant from the crank case to the upper end of the piston, resulting in undesirable smoking and undue and troublesome carbonization, among other things.

Due to the fact that the sleeve or skirt is maintained relativelycool under all normal working conditions, the possibilities of scoring of the inner walls of the cylinder are practically eliminated.

The upper end of the skirt 1 is separated from the head 3 by' an air gap.

The presence of this air gap or air space between the upper edge of the skirt or body section 1 and the lower edge of the peripheral portion 3 of the piston head, insures that-the heat absorbed by the piston head principally will be transmitted inwardly and downwardly so that such portion of it as does reach the skirt oibody by convection will do so at the lower end of the skirt and will not be suflicient in amount to cause the necessary expansion of the skirt to effect binding between the skirt and inner wall of the cylinder or scoring.

It will be understood that my invention compared with the metal of the connector 4,

so that such heat as did pass from the skirt 1 to the head 3 would do so principally by way of the connector 4 rather than from the head to the upperend of the skirt 1.

It will be noted that my compositepiston may be made relatively light in weight, which is of material advantage in assisting in reducing the weight of thereciprocating' parts of the motor.

Pistons of my improved construction will be found to operate comparatively noisele'ssly, smoothly and efliciently within the cylinders of internal combustion motors.

In the present application I have not claimed certain characteristics which the pistons disclosed have in common with the piston shown in my companion application Ser. No. 106,503, filed June 28, 1916, the. common subject-matter referred to being claimed in the latter application.

To those skilled in the art, many modifications of and widely differing embodiments and applications of my invention will suggest themselves, without departing from the spirit and scope thereof. My disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

lVhat I claim is: g

1. A piston for an internal combustion motor, comprising a cast metal head having an inner and an outer flange, a tubular sheet metal guide section, and a separately formed cast tubular connecting member provided with wrist pin bosses and secured near its lower end to said guide section near the lower end of the latter and at its upper end to said inner flange on said head.

2. A piston for an internal combustion motor, comprisin a head cast of a metallic alloy having a relatively low specific gravity as compared with iron and formed with inner and outer depending flanges, a tubular iron guide section, and a separately formed tubular metal connecting member formed with wrist pin bosses and secured near its lower end to said guide section near the lower end of the latter and at its upper end to said inner flange on the head.

3. A piston for an internal combustion motor formed in three separate pieces, towit, a head having an inner and an outer depending flange, a tubular sheet metal guide section and a connecting member formed with wrist pin bosses and secured near its lower end to the lower end of said guide section and at its upper 'end to said inner flange on said head.

v 4. A piston for an internal combustion motor, comprising a cast aluminum alloy head with inner and outer depending flanges, the outer one being grooved to carry piston rings, a sheet metal guide section having its upper end separated by a relatively narrow air gap from the outer flange of said head, and a separately formed tubular connector secured at its lower end to the guide section adjacent the lower end thereof, extending upwardly and connected at its upper end to the inner flange on said head, and having wrist pin bosses formed intermediate its ends.

A piston for an internal combustion motor, comprising a head having inner and outer annular flanges, and a guide section and tubular connector member cast integrally, the guide section being tubular in cross section and said connector being joined to the inner wall thereof adjacent its lower end and extending upwardly therefrom and connected to the inner flange on said head in such manner as to leai e a relatively small" air gap between the upper edge of said guide section and the adjacent edge of the outer flange on the head.

6. A piston for an internal combustion motor, comprising a head formed of a metallic alloy having a lower specific gravity than iron, and a guide section and a tubular connector member cast integrally of iron, the guide section being tubular in cross section and the connector being joined to the inner wall thereof adjacent its lower end and extending upwardly therefrom and connected to the said head in such manner as to leave a relatively small air gap between the upper edge of the skirt and the adjacent wall of said head.

7. A piston for an internal combustion motor formed in three separate pieces, towit, a head cast of a metallic alloy having a relatively low specific gravity as compared with iron, a tubular sheet metal guide section and a tubular connecting member formed intermediate its ends with wrist pin bosses and secured near its lower end to the lower end of said guide section and at its upper end to said head.

8. A piston for an internal combustion motor, comprising a cast metal head provided with an inner and an outer flange, a tubular sheet metal guide section, and means formed with wrist-pin bosses for connecting the lower end of said guide section to the inner flange of said head, said means being mechanically secured to said inner flange without obstructing the opening to the lower surface of the head within said inner flange.

9. A piston for an internal combustion motor, comprising a cast metal head formed of an alloy having a lower specific gravity than iron, and provided with an inner and an outer flange, a tubular sheet metal guide section. and means formed with wrist-pin bosses for connecting the lower end of said guide section to the inner flange of said head. said means being mechanically ,secured to said inner flange without obstructing the opening to the lower surface of the head within said inner flange.

10. A piston for an internal combustion motor, comprising a cast metal head, pro vided with an inner and an outer flange, a tubular sheet metal guide section, and an annular member formed separately free from said head and provided with wrist pin bosses and connected near its lower end with said guide section near the lower end ofthe latter and at its upper end to the in ner flange on said head, whereby the lower surface of the head surrounded by the inner flange is open for the radiation of heat.

In testimony whereof I aflix my signature in the presence of two witnesses.

LOUIS P. MOOERS.

Witnesses:

ELISE H. ALEXANDER, EDWARD R.- ALEXANDER. 

